I have a UTH (controlled by the ReptiTemp 500R) and have been using a heat lamp for the cool side/overall temp. Still haven't been able to get it much past 77. The heat lamp drops the humidity by about 15-20 per cent. I've been combating that by having 2 soaking wet paper towels in/on plastic bowls, as well as slightly dampening spots here 'n' there on the substrate paper towels. It's been working as we got a perfect shed last week, even with the humidity at just below 50. It sure is a battle, though. (We're using a glass tank, and will eventually move to a tub, which I hear is easier to control temps and humidity with.)